Feeds:
Posts
Comments

Archive for May, 2020

I have just been looking at the GPCC dataset, using Matlab to extract and plot monthly data for different time periods including comparisons. I’d like to compare actual with the output of various climate models over similar time periods – and against future simulations under different scenarios.

Have any readers of the blog done this? If so I’d appreciate a few tips having run into a few dead ends.

What I’m looking for – monthly gridded surface precipitation.

GPCC has 0.5ºx0.5º and 2.5ºx2.5º datasets that I’ve downloaded so the same gridded output from models would be wonderful.

I have found:

–  The CMIP5 Data is now available through the new portal, the Earth System Grid – Center for Enabling Technologies (ESG-CET), on the page http://esgf-node.llnl.gov/

–  https://www.wcrp-climate.org/wgcm/references/IPCC_standard_output.pdf

Table A1a: Monthly-mean 2-d atmosphere or land surface data (longitude, latitude, time:month).

CF standard_name; output; variable name;  units;  notes  –
precipitation_flux; pr; kg m-2 s-1;   includes both liquid and solid phases.

So I think this is what I am looking for.

–  https://www.ipcc-data.org/sim/gcm_monthly/AR5/Reference-Archive.html gives a list of different experiments within each climate model. For example – the MPI model, I expect that historical and rcp.. are the ones I want. I would have to dig into MPI-ESM-LR and -MR which I assume are different model resolutions.

But when I work my way through the portal, e.g. https://esgf-data.dkrz.de/search/cmip5-dkrz/ I find a bewildering array of options and after hopefully culling it down to just monthly rainfall from the MPI-LR model, there are 213 files:

I can easily imagine spending 100+ hours trying to establish which files are correct, trying to verify.. So, if any readers have the knowledge it would be much appreciated.

————

Just for interest, here are a few graphs produced from GPCC using Matlab. I checked a couple of outputs against samples produced from their website and they seemed correct.

I set the max monthly rainfall on the color axis to increase contrast for most places in the world – 4 different 10-year periods:

GPCC Precipitation data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at https://psl.noaa.gov/

And a delta, % difference:

GPCC Precipitation data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at https://psl.noaa.gov/

Read Full Post »